Various assemblies, including vehicles and industrial machinery, have members (fastened members) fastened together by bolts, rivets, and other fastening parts. In automobiles, for example, the seats, seat belts, doors, and other members are fastened to the vehicle body by bolts.
These various assemblies are subject to the effects of all kinds of accidents. During an emergency in which an airbag expands, for example, in cases in which an automobile is subjected to the effects of a collision or any other accident, it is preferable that the passengers rapidly exit the vehicle of their own volition. It is therefore even more preferable that members hindering the passengers from exiting the vehicle be rapidly removed from the vehicle body. Moreover, these members should not be removed from the vehicle body under normal circumstances.
There is a member disengagement apparatus for immediately disengaging fastened members fastened by fastening parts. This member disengagement apparatus is disclosed in Japanese Patent Laid-Open Publication No. 7-27119 (JP-A-7-27119).
The member disengagement apparatus disclosed in the 7-27119 publication has fastening parts that are configured from bolts and nuts, wherein the nuts are secured to one of fastened members with the aid a low-melting material. When the fastened state is released by this member disengagement apparatus, the low-melting material is heated and melted with a heater to rapidly separate the nuts from one of the fastened members. As a result, the fastened members are rapidly disengaged.
It has therefore been suggested that fastening parts that need to be rapidly separated from the vehicle body of such an automobile during emergencies can be provided with the member disengagement apparatus disclosed in the 7-27119 publication. In this case, members that hinder the passenger from exiting the vehicle can be rapidly removed from the vehicle body during emergencies. However, it is preferable that it not be possible for the passenger to accidentally operate the member disengagement apparatus under normal circumstances.
An apparatus designed so that the passenger cannot accidentally disengage fastened members is used to prevent such accidental release. This apparatus is disclosed in Japanese Patent Laid-Open Publication No. 2000-233711 (JP-A-2000-233711) as a passenger protection apparatus included in ride cars in amusement parks.
The passenger protection apparatus disclosed in the 2000-233711 publication comprises a seat belt for restraining the passenger in the car seat, wherein the seat belt buckle is covered by a protective cover that can be locked. A lock releasing switch for releasing the locked state of the protective cover is placed in an operating room positioned at a distance from the ride cars. The passenger cannot release the locked state of the buckle covered by the protective cover. When the locked state of the protective cover needs to be released, the operator operates the lock releasing switch in the operating room.
In view of this, one possibility is to combine the passenger protection apparatus disclosed in the 2000-233711 publication with the member disengagement apparatus disclosed in the 7-27119 publication, and to use this combination in an automobile. In this case, covering the release operation unit of the member disengagement apparatus by a protective cover makes it possible to prevent the passengers in the vehicle from accidentally operating the release operation unit.
However, since the release operation unit is covered by a protective cover, members that hinder the passenger from exiting the vehicle during emergencies cannot, as they are, be removed from the vehicle frame by the passenger's own volition. In addition to automobiles and other vehicles, this is also true for various other assemblies including industrial machinery.
In view of this, there is a need for a technique whereby a person directly involved with an assembly can rapidly disengage the fastening parts only during emergencies in a direct manner.